Communication method for database

ABSTRACT

A method is provided of communication between a user and a database of Patents and also of the display and the interactive exploration of data on information of interest relating to Patents/Patent applications. The method comprises:
         the generation, by means of an access interface, of a request allowing the database to be interrogated based on at least one selection criterion entered into the access interface;   the interrogation of the database by means of the request and the loading of bibliographical data for the Patents/Patent applications found, the downloaded bibliographical data comprising data on the technological category;   the processing of the bibliographical data, the processing comprising an analysis of co-occurrences comprising the determination of a number of co-occurrences of data on the technological category for all of the Patents/Patent applications found;   the displaying, in interactive graphical and/or textual form, of a result and/or of an interpretation of the analysis of co-occurrences.

TECHNICAL FIELD

In general terms, the invention relates to the communication between adatabase and a user. More precisely, the invention relates to a methodfor displaying and for interactive exploration of data on information ofinterest relating to Patents/Patent applications.

TECHNOLOGICAL BACKGROUND AND TECHNICAL PROBLEM

Patent information includes the technical content (description, claimsand drawings) of the Patent documents (publications of Patentapplications or of Patents) together with bibliographical data, such asthe data on the filing party or parties, the inventor or inventors,technical classification information, the priority date, the filingdate, etc. It constitutes the first source of first-hand information onnovel and innovative technologies.

There are two main uses of the Patent information. The qualitativeanalysis relates to the content of the individual documents. Thequantitative analysis relates to sets of Patent documents andessentially to their statistical processing.

Numerous Patent offices maintain Patent databases freely accessible online to the public. One of the major databases to be mentioned in thiscontext is “Espacenet”, made available by the European Patent Office.Other databases are marketed by private organizations. These databases,e.g. Derwent Innovation, Questel Orbit, PatBase, etc., are supplied frompublic databases but offer added value in the form of complementaryinformation, of access interfaces and/or of higher performance dataprocessing tools.

This industry has developed numerous types of data display formatsbased, at least in part, on the IPC (International PatentClassification) classification data. In the interfaces, a common displayformat is to represent the absolute distribution of the classes within apool of Patents. One example of such a representation is the pie chart.In this type of display format, only the number of occurrences of eachclass within the pool of Patents is represented, i.e. the number oftimes an IPC class is cited in the Patents of the pool. The utility ofthis type of graph is somewhat limited for extracting information.Moreover, the reading of the diagram is difficult because the displaytools typically display either the alphanumeric symbol of the class orthe whole title (the wording) of the class. There exist variants of the“pie chart” theme that facilitate the reading. The basic idea remainshowever that where the number of Patents in an IPC class is higher, themore space (surface area) is allocated to this class.

Some commercial display tools of the Patent databases include a“technological clustering”. The pool of Patents is, in this case,divided into technological fields and sub-fields according to unknowncriteria. Although these representations are often visually successful,they are difficult to interpret, because the segmentation analysisalgorithms (known as “clustering algorithms”) operate as “black boxes”.

Another example of display format based, amongst other things, on IPCdata is the representation in “Patent landscape” mode or “technologylandscape” mode. The pool of Patents is, in this case, represented by aseries of key words disposed according to a mutual proximity indicatorin a 2D or 3D space. The key words may be produced by heterogeneous datafrom the pool of Patents: IPC classification, abstract, claims, etc. Themode of obtaining the key words together with the calculation of thedistance between the key words is opaque.

The conclusions drawn from representations of “technological clustering”or of “Patent landscapes” accordingly contain a significant element ofsubjectivity, or of speculation. There is furthermore the risk thatniche applications only appear whenever the corresponding segmentreaches a certain size or a corresponding key word is recognized by thealgorithm as “worthy” of being displayed.

GENERAL DESCRIPTION OF THE INVENTION

According to one aspect of the invention, a method of communication isprovided between a user and a database of Patents and also for thedisplay and interactive exploration of data on information of interestrelating to Patents/Patent applications, e.g., bibliographical data,notably IPC data. The method comprises:

-   -   the generation, by means of an access interface, of a request        allowing a database of Patents (commercial or free access) to be        interrogated using at least one selection criterion entered into        the access interface by the user;    -   the interrogation of the database by means of the request and        the downloading (typically via a local network and/or the        Internet) of bibliographical data for the Patents/Patent        applications found by the database, the bibliographical data        downloaded comprising data on the technological category;    -   the processing of the bibliographical data, the processing        comprising a co-occurrence analysis, the co-occurrence analysis        comprising the determination of a number of co-occurrences of        data on the technological category for all of the Patents/Patent        applications found;    -   the displaying, in interactive graphical and/or textual form, of        a result and/or of an interpretation of the co-occurrence        analysis.

The data on the technological category will preferably comprisetechnological classification symbols according to a system ofhierarchical classification, for example, IPC, CPC (Cooperative PatentClassification) USPC (United States Patent Classification) or otherclassification symbols.

As indicated hereinabove, the analysis of co-occurrences comprises thedetermination of the number of co-occurrences of data on thetechnological category for all of the Patents/Patent applications found.In other words, the analysis of co-occurrences asks the question to knowhow many times the same group of data on the technological categoryappears in the Patents/Patent applications of the set examined.According to a preferred embodiment of the method, the analysis ofco-occurrences relates to doublets (pairs) of data on the technologicalcategory, where the order of the data on the technological category maybe either taken into account or neglected (the second alternative beingpreferred).

As an alternative or in addition, the analysis of co-occurrences mayrelate to triplets (sets with three elements) of data on thetechnological category.

The analysis of co-occurrences may comprise the creation of a table ormatrix representing the set of all the possible combinations of data onthe technological category. Subsequently, for each combination, thenumber of Patents having this combination of data on the technologicalcategory (as such or as a sub-combination) is determined. The computerexecuting this part of the method may perform this determination byrunning through the list of Patents and incrementing counters associatedwith the various combinations of data on the technological categoryfound for each Patent.

Preferably, the display comprises control objects made available to theuser (e.g. buttons, icons, thumbwheels, hyperlinks, etc.) whoseactuation or manipulation (by a mouse, a touch screen or any otherpointing device) leads to a new execution of the analysis ofco-occurrences with modified parameters. For example, the analysis ofco-occurrences could be based on the IPC classification down to thesub-class level, whose symbol is composed of a letter followed by anumber with two digits and by another letter. The control objects couldbe configured to trigger a new execution of the analysis ofco-occurrences that could be based on a higher level (section or class)or lower level (main group or sub-group) of the IPC classification.

Additionally or alternatively, the display may comprise control objectsmade available to the user whose actuation or manipulation leads to afiltering of the Patents/Patent applications found by the database andthe generation of a corresponding sub-set of Patents/Patentapplications. The actuation or the manipulation of the control objectscould also lead to an execution of an analysis of co-occurrences of thedata on the technological category restricted to the sub-set of thePatents/Patent applications.

According to a particularly preferred embodiment of the invention, thedisplay of the result of the analysis of co-occurrences will take theform of a network graph in three dimensions. Of course, a display in theform of a network graph in two dimensions is also possible.

The display may comprise the displaying of the result of the analysis ofco-occurrences in the form of an interactive network graph. Such anetwork graph could comprise nodes and links respectively between twonodes, the nodes representing technological classification symbols andthe links between two nodes the co-occurrences of the technologicalclassification symbols corresponding to the two connected nodes.

A visual attribute of each node (e.g. its size, its diameter, thethickness of its contour, the intensity of its colour, its transparency,etc.) could reflect the number of occurrences of the correspondingtechnological classification symbol and a visual attribute of each link(e.g. its thickness, the intensity of its colour, its transparency,etc.) could reflect the number of co-occurrences of the technologicalclassification symbols corresponding to the two connected nodes.

Preferably, the nodes and/or the links form interactive elementsconfigured for triggering, following an action by the user (e.g. singleclick, right click, double-click, etc.), a new execution of the analysisof co-occurrences with modified parameters together with a new displayof the result of the new analysis of co-occurrences in the form of aninteractive network graph.

Additionally or alternatively, the nodes and/or the links couldconstitute interactive elements configured for triggering, following anaction by the user, a filtering of the Patents/Patent applications foundby the database, the generation of a corresponding sub-set ofPatents/Patent applications, execution of an analysis of co-occurrencesof the data on the technological category restricted to the sub-set ofPatents/Patent applications and a display, in the form of an interactivenetwork graph, of the result of the analysis of co-occurrencesrestricted to the sub-set. The analysis of co-occurrences could comprisesimple applications of graphical theory, in order to for exampleindicate the distance between two nodes, according to the actions of theuser.

The analysis of co-occurrences could relate to triplets of technologicalclassification symbols. In this case, the display could comprise thedisplay of the result of the analysis of co-occurrences in the form ofan interactive network graph with nodes and complex links between threenodes, respectively, the nodes representing technological classificationsymbols and the complex links between three nodes the co-occurrences ofthe technological classification symbols corresponding to the threeconnected nodes. The complex links could be represented by colouredtriangles, stars with three apices, or similar shapes, connecting thethree respective nodes.

Preferably, the representation of the interactive graph intended to bedisplayed is generated by means of an artificial intelligence algorithmtaking into account the complexity of the graph. The algorithm could,e.g., adjust parameters reducing the complexity of the representation ifit detects that the representation would otherwise become too cluttered.The display could comprise graphics control elements (sliders, rotaryselector switches, or others) allowing the user to change the parameterschosen by default and/or by the algorithm.

The representation of the interactive graph preferably comprises labelsassociated with the nodes and/or with the links. The labels may begenerated on the basis of definitions of the hierarchical classificationsymbols. Preferably, the labels displayed are summaries of the officialidentifiers. An artificial intelligence algorithm could be employed tosummarize the official identifiers and generate labels adapted to thedisplay of the graph.

BRIEF DESCRIPTION OF THE DRAWINGS

Other advantages and features of the invention will become apparent fromthe detailed description of one advantageous embodiment presentedhereinbelow, by way of illustration, with reference to the appendeddrawings which show:

FIG. 1: one example of network graph illustrating the occurrences andthe co-occurrences of technological classes of a set of generic Patents;

FIG. 2: a variant of the network graph in FIG. 1 with a “zoom” onto theinner details of the class 1;

FIG. 3: a variant of the network graph in FIG. 2 partially showing theinner details of the class 2, in particular its largest sub-class orthat having the most links;

FIG. 4: one example of a network graph illustrating the occurrences andthe co-occurrences of technological classes of a real set of Patents.

DETAILED DESCRIPTION

One preferred example of the invention relating to the field of Patentinformation will be discussed in the following. The implementationprovided facilitates the analysis of a pool of Patents by means of aninteractive graphical representation (display) of this pool. In thefield of Patent information, those skilled in the art will often need toanalyze data associated with a large number of Patents previouslyidentified according to certain criteria (key words, assignees,inventors, technological classes, etc. or combinations of the latter).The pool of Patents obtained corresponds (potentially after manualtidying up) to a well defined topic of interest—on a technology, afunction, a group of assignees, etc.—for which the Patent analyst wishesto extract information and to provide interpretations. The display ofthe data associated with this pool allows relevant information to bequickly extracted. For example, the number of Patents per assignee maybe displayed, which allows the main actors in the field of inventionassociated with the pool to be immediately deduced from this.

The embodiment discussed by way of example makes use of the IPCtechnological classification data. Patent offices classify each Patentaccording to a very structured and hierarchized classification oftechnical fields. A pool of Patents therefore comprises a set of IPCclasses. The most represented classes in the pool indicate the maintechnical fields to which the pool of Patents relate. The analysis ofthe data on the representation of the classes in the pool allowsrelevant information to be extracted on the structuring of the pool, andhence on the structuring of the specific topic of interest, object ofthe Patent analysis.

In order to assist the Patent analyst in his/her interpretation of thepool and in the exploration of the data relating to it, a display of theIPC classes of the pool is provided by means of a representation in theform of a network graph (see FIG. 1). Each Patent or Patent applicationis classed in one or more technological classes of the IPCclassification. The network graph comprises nodes 1, 2, 3, 4, 5 andlinks L12, L24, L45 respectively between two nodes: the nodes representtechnological classification symbols and the links between two nodes theco-occurrences of the technological classification symbols correspondingto the two connected nodes. The technological classification symbolsrepresented by the nodes may belong to various hierarchical levels ofthe IPC. The complete IPC symbol corresponds to the “main group” or“sub-group” levels. A network graph whose nodes all represent a completeIPC symbol can become very complex and cluttered if the number ofPatents in the pool increases. In the implementation provided, thenetwork graph is interactive, so as to allow the user to reduce or toincrease the complexity of the graph over the entirety or one (of the)part(s) of the network.

The size of each node is linked to the relative weight of thecorresponding class in the pool; similarly, the thickness of each linkdepends on the number of Patents connecting the two classes, i.e. on thenumber of Patents which belong to both of the two connected classes.

In order to facilitate the analysis, the display includes a label T1,T2, T3, T4, T5 next to each node 1, 2, 3, 4, 5 using the identifier ofthe associated class (or a summary of the latter) and/or thealphanumeric symbol of the class.

The identifier of the class is sometimes long (several tens of words),in particular in the highest hierarchical levels of the classification.If the identifier of the class were completely displayed as a label foreach node, the graph would risk becoming unreadable and hence unusable.In order to overcome this problem, semantic analysis techniques andautomatic processing of the natural language are applied so as to reducethe identifier to a small number of key words. The length of theidentifier and the size of the font are adapted on a case by case basisto the space available in the display.

In this way, the Patent analyst does not have to look for the meaning ofthe IPC symbols in the IPC classification and can quickly extractrelevant information on the Patent pool in question, and hence on thespecific topic of interest.

As explained above, the Patent analyst can choose the level of detail ofthe classes displayed according to his/her preferences, from the highesthierarchical level of the IPC classification down to the lowest. Thedisplay of the identifier of the class is, in this case, adaptedaccording to the chosen hierarchical level.

By way of illustration, a more detailed example is discussed hereinbelowwith the aid of the figures. It is assumed that the search in thedatabase of Patents has returned a pool (set) of Patents in which 5classes (numbered 1 to 5) are represented, with certain connexionsbetween the classes. Table 1 hereinbelow informs on:

-   -   in the diagonal, the number of Patents belonging to the        respective class, and    -   in the upper right part, the co-occurrences of all the pairs of        classes, i.e. the number of Patents that belong to both the        class indicated by the column and the class indicated by the        row.

For example, in this pool, 7 Patents belong to the class 1 and there are6 Patents categorized in both the classes 1 and 2.

TABLE 1 Class n^(o) 1 2 3 4 5 1 7 6 0 0 0 2 9 0 3 0 3 3 0 0 4 4 1 5 3

It is noted that the lower left part of the table has been left empty inorder to avoid inserting redundant indications. The usual matrices ofgraphical theory (notably the weighted similarity matrix) may be deducedfrom this table, and usefully exploited in the analysis of theco-occurrences.

A network graph associated with the pool of this example is shown inFIG. 1. It can be seen that the class 1 only has co-occurrences with theclass 2 (on 6 Patents, link L12). On the other hand, the class 2 hasfurther co-occurrences with the class 4 (on 3 Patents, link L24). Thelatter appear together with the class 5 on a single Patent (link L45).The class 3 is an isolated class.

The display obtained can assist the Patent analyst in the interpretationof the data of the pool. The assumption is that a Patent filed underseveral separate classes corresponds to an overlap between theseclasses. In particular, when the classes are very far apart in the IPCstructuring (it is possible to define a distance in the IPC as afunction of the number of branches that need to be traversed in the treestructure in order to go from one class to the other), a set of Patentsbelonging to heterogeneous classes involves an interdisciplinary orreconciliation effort between the associated technological fields.

The information coming from the display of the data can allow the Patentanalyst to make several relevant interpretations. For example, thePatent analysis may be used to search for potential partners. Taking thecase where, over the well-defined topic of interest associated with thepool of Patents, a particular niche application is sought. This nicheapplication is present in a few Patents, but does not correspond to anindustrial sector likely to market technologies corresponding to theniche application of (FIG. 1, class 5). The display obtained allows thetechnological field and/or industrial sector likely to provide solutionsfor developing the niche application (namely the class 4) to beidentified. It can be observed that the class 5 does not have a directlink with the class 2, which however represents the main technologicalfield of the defined topic of interest, although there does exist afairly strong link between the classes 2 and 4 (link L24). The Patentanalyst may therefore pose the question whether it is not possible toestablish a direct link between the classes 2 and 5, as a complement tothe class 4 or by bypassing the latter.

Another exemplary application is the analysis of the innovation dynamicby means of an identification of technology transfers between industrialsectors. The case is considered where the defined topic of interest isdominated by a well established technological field (here represented bythe class 2), carried by an industrial sector and a set of clearlyidentified technological fields. On this topic of interest, a newapplication is beginning to emerge, carried by a few actors andassociated with a distinct technological field (here represented by theclass 4). The display obtained allows a significant filing of Patents tobe identified belonging to the 2 associated classes, and hencepotentially a transfer of technologies, in progress or actual, between amature technological field and an emerging field.

The network graph displayed as the result of the analysis isinteractive. Various types of control elements may be generated and madeavailable to the user. In the network graph in FIG. 1, the nodes 1, 2,3, 4 and 5 are configured as interactive elements. If the user rightclicks on one of the nodes, a scrolling menu with the various commandsavailable is displayed. One of the commands could trigger a drop in thehierarchy of the technology classification to a lower level. Thiscommand leads to the display of more detail within the selected class.When the user chooses to display the detail of the class 1, theprogramme re-does the analysis of the occurrences and of theco-occurrences under the constraint that the hierarchically lowerclasses are processed individually. One result of this step is found inTable 2, hereinbelow:

TABLE 2 Class no 1.1 1.2 1.3 2 3 4 5 1.1 1 0 0 0 0 0 0 1.2 2 1 1 0 0 01.3 5 5 0 0 0 2 9 0 3 0 3 3 0 0 4 4 1 5 3

The corresponding network graph is illustrated in FIG. 2.

In a similar manner, another command accessible via the interactivegraph could result in a raising of the hierarchy of the technologyclassification. In this case, several classes would be combined into ahierarchically higher class.

FIG. 3 illustrates another functionality of the analysis tool, namelythe possibility for the user to display, inside of a node (here that ofthe class 2), a node corresponding to the largest sub-class or thesub-class having the most links (ici: 2.x).

Another command, accessible via the interactive graph, could lead to thecalculation of the distance of the node selected with respect to anothernode previously selected by the user.

Exemplary Application

Assume that the problem posed to the Patent analyst is the following: inthe framework of night vision of watches, and of the illumination of thehands and dials, find a substitute for superluminova (trademark) using abioluminescent pigment. The specific topic of interest of the Patentanalyst is therefore bioluminescence. The idea is to find thetechnological fields the most likely to provide bioluminescenttechnologies adapted to the illumination of the cover parts for watchesand clocks.

A pool of around 1000 Patents can be extracted according to a search bykey words (title/abstract/claims containing “bioluminescen*”). A quickexamination of the pool shows that bioluminescence is mainly used inbiomedical research as a biological marker. The two classes the mostrepresented in the pool are the classes (or set of classes) C12(biochemistry) and G01 (physical measurements). The class relating tolighting applications (F21) is not represented to any extent within thepool. It may be deduced from this that the lighting applications ofbioluminescence are not very well developed with respect to thebiomedical applications. The application sought by the Patent analyst istherefore a niche application. Table 3 informs on a part of theoccurrences and co-occurrences observed over all of the Patents. Adisplay by associated network graph is shown in FIG. 4.

TABLE 3 classes C12 G01 C07 A61 A23 F21 C12 235 456 126 57 3 16 G01 126132 452 12 0 C07 134 325 0 4 A61 12 15 17 A23 25 18 F21 3

The graph shows, amongst other things, the co-occurrences of the classF21 (lighting), and thus allows the search for partners to be directed.It is noted that the graph immediately gives access to a labelexplaining the classes, rather than a single alphanumeric symbol, whichallows it to be quickly understood what these classes cover.

It can immediately be seen that bioluminescence does not yet have anylink with the classes relating to the watch and clock industry (G04).Accordingly, it will probably therefore be necessary to proceed viaadaptations and transfers of technologies in order to achieve thedesired application. Over the two main classes of the pool (C12 andG01), F21 does not have any direct link with the G01. It may be deducedfrom this that it is better to prioritize the searches towards thetechnological fields linked to the class C12. Furthermore, the link tothe organic chemistry class (C07) is weaker than for the other classes.It may be deduced from this that it is better to prioritize the searchestowards the other classes by, for example, studying the bioluminescenceapplications in the agri-food industry (A23). A weighted calculation ofdistance, using the weighted similarity matrix, would allow the size ofthe classes adjacent to F21 to be confirmed and to be quantified.

Although particular embodiments have just been described in detail,those skilled in the art will appreciate that various modifications andalternatives to the former may be developed in the light of the overallteaching provided by the present disclosure of the invention.Consequently, the specific arrangements and/or methods describedherewithin are intended to be given solely by way of illustration, withno intention to limit the scope of the invention.

1. Method of communication between a user and a database of Patents andalso of the display and interactive exploration of data on informationof interest relating to Patents/Patent applications, comprising: thegeneration, by means of an access interface, of a request allowing thedatabase of Patents to be interrogated based on at least one selectioncriterion entered into the access interface by the user; theinterrogation of the database by means of the request and thedownloading of bibliographical data for the Patents/Patent applicationsfound by the database, the downloaded bibliographical data comprisingdata on the technological category; the processing of thebibliographical data, the processing comprising an analysis ofco-occurrences, the analysis of co-occurrences comprising thedetermination of a number of co-occurrences of data on the technologicalcategory for all of the Patents/Patent applications found; thedisplaying, in interactive graphical and/or textual form, of a resultand/or of an interpretation of the analysis of co-occurrences.
 2. Themethod according to claim 1, in which the analysis of co-occurrencesrelates to pairs of data on the technological category.
 3. The methodaccording to either of claims 1 and 2, in which the analysis ofco-occurrences relates to triplets of data on the technologicalcategory.
 4. The method according to any one of claims 1 to 3, in whichthe display comprises making control objects available to the user whoseactuation or manipulation leads to a new execution of the analysis ofco-occurrences with modified parameters.
 5. The method according to anyone of claims 1 to 4, in which the display comprises making controlobjects available to the user whose actuation or manipulation leads to afiltering of the Patents/Patent applications found by the database andthe generation of a corresponding sub-set of Patents/Patentapplications.
 6. The method according to claim 5, in which the actuationor the manipulation of the control objects also leads to an execution ofan analysis of co-occurrences of the data on the technological categoryrestricted to the sub-set of the Patents/Patent applications.
 7. Themethod according to any one of claims 1 to 6, in which the displaycomprises the display of the result of the analysis of co-occurrences inthe form of a network graph in two or three dimensions.
 8. The methodaccording to any one of claims 1 to 7, in which the data ontechnological categories comprise technological classification symbolsaccording to a system of hierarchical classification, for example IPC,CPC or USPC classification symbols.
 9. The method according to claim 8,in which the display comprises the display of the result of the analysisof co-occurrences in the form of an interactive network graph with nodesand links respectively between two nodes, the nodes representingtechnological classification symbols and the links between two nodes theco-occurrences of the technological classification symbols correspondingto the two connected nodes.
 10. The method according to claim 9, inwhich a visual attribute of each node reflects the number of occurrencesof the corresponding technological classification symbol and a visualattribute of each link reflects the number of co-occurrences of thetechnological classification symbols corresponding to the two connectednodes.
 11. The method according to either of claims 9 and 10, in whichthe nodes and/or the links constitute interactive elements configuredfor triggering, following an action by the user, a new execution of theanalysis of co-occurrences with modified parameters together with a newdisplay of the result of the new analysis of co-occurrences in the formof an interactive network graph.
 12. The method according to any one ofclaims 9 to 11, in which the nodes and/or the links constituteinteractive elements configured for triggering, following an action bythe user, a filtering of the Patents/Patent applications found by thedatabase, the generation of a corresponding sub-set of Patents/Patentapplications, execution of an analysis of co-occurrences of the data onthe technological category restricted to the sub-set of thePatents/Patent applications and a display, in the form of an interactivenetwork graph of the result of the analysis of co-occurrences restrictedto the sub-set.
 13. The method according to any one of claims 8 to 12,in which the analysis of co-occurrences relates to triplets oftechnological classification symbols, in which the display comprises thedisplay of the result of the analysis of co-occurrences in the form ofan interactive network graph with nodes and complex links respectivelybetween three nodes, the nodes representing technological classificationsymbols and the complex links between three nodes the co-occurrences ofthe technological classification symbols corresponding to the threeconnected nodes.
 14. The method according to any one of claims 8 to 13,in which the representation of the interactive graph intended to bedisplayed is generated by means of an artificial intelligence algorithmtaking into account the complexity of the graph.
 15. The methodaccording to any one of claims 8 to 14, in which the representation ofthe interactive graph comprises labels associated with the nodes and/orwith the labels, the labels being generated on the basis of definitionsof the hierarchical classification symbols.
 16. The method according toany one of claims 8 to 15, in which the analysis of co-occurrencesapplies simple elements of graphical theory, such as the calculation ofthe distance between nodes selected according to the actions of theuser.